This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The ability to detect and eliminate DNA damage is essential for the survival of every organism. As such the response to DNA damage is tightly regulated and requires the coordinated activity of several signal transduction pathways. Many of the proteins involved in the involved signaling processes have been identified in vitro using cell cultures, and it is well known how the response to DNA damage is regulated in somatic cells. The germ line though has been left nearly untouched in this regard, mainly because of its difficult access and very limited amounts of material. Recent evidence however suggests major differences between the regulation of the stress response in somatic cells and that in germ cells. To unravel the signaling network regulating the germ line response to DNA damage, we will apply mass spectrometry and take advantage of the emerging model organism Nematostella vectensis. The starlet sea anemone Nematostella vectensis is in contrary to mammals one of the few sequenced organisms from which homogenous populations of oocytes can be obtained in amounts sufficient for mass spectrometry. In this study we will develop sample preparation methods to enrich for signaling proteins and use the MudPIT technology for identification of the proteins. The resulting data should allow us an unbiased look into the cellular events following genotoxic stress in vivo.